


Double, Double

by FallacyFallacy



Category: Star Trek (2009)
Genre: Bodyswap, Established Relationship, M/M, Masturbation, Mirrors, Mutual Masturbation, PWP, Transporter Malfunction
Language: English
Status: Completed
Published: 2011-08-20
Updated: 2011-08-20
Packaged: 2017-10-22 21:01:49
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,519
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/242539
Author URL: https://archiveofourown.org/users/FallacyFallacy/pseuds/FallacyFallacy
Summary: <blockquote class="userstuff">
              <p>Caught in a transporter malfunction, Kirk and Spock switch bodies. While Spock works on fixing it, Jim decides to test this thing out. Written for my Mirrors/Doubles square for Kink_bingo.</p>
            </blockquote>





	Double, Double

**Author's Note:**

> The main idea of this fic is a veeeeeeeery old one that goes right back to my Mohinder/Sylar days. Pretty happy to finally write it out!

The Captain stepped off the transporter, nodding at the technician. “Good work. All right, guys, let's meet up to debrief in the usual place in 30 minutes. We did well today.”

...and that was when he realized that everyone was staring at him. And not in a good 'my god my Captain is sexy' kind of way, but in a rather disturbing 'holy shit, he got stabbed and doesn't realise it' kind of way.

“... Mr. Spock,” Scotty breathed, looking incredulous.

Concerned, Kirk turned to see just what was so shocking about Spock, and found himself looking at – himself.

Fuck it, he cursed mentally, eye twitching. Not again. The first time they'd had an evil Kirk running around had been bad enough, but again? (Well, that wasn't including the time they'd had an evil Kirk without the good one with him. Or the time it'd just been some evil guy pretending to be him. Or the time – now that he thought about it, he got spit into two pretty often. It was probably one of life's great ironies that not _one_ of those situations had given Spock the opportunity for a Jim sandwich.)

But then the other him raised his eyebrow, placed his hands behind his back, and murmured, “Fascinating...”

“...Spock.”

Spock stepped forward. It was very weird to be looking into one's own reflection breathing and walking around like that – still was, regardless of the number of times it'd happened to him. Somehow, this was weirder, though. His face wasn't designed to be displaying that level of expressionlessness. On Spock it was normal, even kinda cool. On him it just looked eerie.

“Captain.” Goddammit, he was used to detecting expressions in Spock's face, not his own. He was back to square one here, and he spared a moment to be irritated. “It appears that we are not in our rightful bodies.” Somehow, Jim got the impression that that wasn't what Spock wanted to say.

“No shit,” he mumbled without thinking. Then it clicked, and in an instant Jim was back to Captain mode. “Okay, so, I guess we gotta figure out how this happened, too.”

The technician hastily turned back down to her console. “I don't know,” she thought aloud, opening up some diagnostics. “It should be working fine... Unless it's some kind of bug...”

“It couldnae be!” Scotty declared firmly, shaking his head. “I know this baby inside an' out, and I never caught whiff of a bug o' this sort!”

“Well, it was something, anyway.” Was it just him, or was this room ridiculously cold? It was distracting. “I want you and your crew working on that. We won't have any more beaming to do until we reach our next destination, but I want it fixed by then, is that clear?”

Scotty and the girl nodded. “Aye, sir.”

“Good.” He turned back to Spock and resisted the urge to double-take again. It was just such a truly odd thing to look at he felt his own incredulity every time he saw it again. “Well, I guess we'll discuss what to do about this at debriefing?”

His doppelganger nodded stiffly. Kirk wasn't sure if it was just the weirdness of seeing someone as emotional as himself acting so blankly or if Spock was overcompensating. Now that he thought about it, if it was weird to see himself acting unemotionally, the other way around must be even worse. Feeling slightly guilty, Kirk made an attempt to school his expression.

“Right. We'll be right there, then.”

~

The meeting over, Kirk stretched his muscles. The mission had been pretty straightforward for once, so they'd spent most of their time discussing his and Spock's situation. Unfortunately, apart from 'just deal with it until we can figure out how to reverse it' no-one really seemed to have any ideas about what to do. Spock and Scotty had some theories, but they'd need to work them out a bit more before testing them.

“Are you coming back with me?”

The Kirk in front of him shook his head. At first he had had to keep reminding himself that this was Spock he was looking at but he was getting more and more used to it. It was still weird as hell, but after being together for a year and working together for even longer Jim knew Spock's expressions well enough now to pick them instantly even on his own face.

“My presence is required here. My expertise will be of use, and I will be able to ensure that Mr. Scott completes all theoretical calculations before beginning testing.”

“Oy! I dinnae need a babysitter, Mr. Spock!”

Kirk laughed. “No, I think he's got you down perfectly, Scotty.”

But Scotty was wincing. “Och, please stop doing tha', Jim. 'Tis very unsettlin'.”

“Doing what?”

“I believe Mr. Scott is referring to your expressiveness, Captain.”

“Oh, right.” Jim frowned, then tried to stop himself. “Fuck, this is hard. How the hell do you do this all day?”

Spock tilted his head. “Years of practice. Of course, not everyone has the talent necessary.”

Jim rolled his eyes. “Yeah, whatever. Don't you have equations to do?”

Spock nodded. “I will return to our quarters before dinner.”

“Awesome.”

As he returned to his shared quarters, Jim wondered how long this...whatever it was...would last. He wasn't all that concerned when it came to the running of the ship – the officers has all agreed that there wasn't really any reason not to tell the crew, who had been put in far stranger situations already. Apart from a few curious looks, they probably wouldn't question it much. Missions wouldn't be too bad, either. Even on diplomatic missions where they couldn't necessarily explain their situation he trusted them both to act their roles accordingly. It was personal time he was worried about. It wasn't that he'd hate to be in Spock's body (no innuendo intended) or a Vulcan, but he did like his own body and would prefer to be in it. And given how much Spock had fought to be recognised as a Vulcan, he couldn't imagine that suddenly being fully Human was very fun at all.

Entering their room, Kirk reflexively began to shrug off his shirt. He always felt like a shower after a mission like this – he wasn't injured, but he probably had all kinds of alien dirt and who knew what else all over him. He wasn't feeling as sweaty as normal, though – that was probably because of Spock's biology. It would make sense for a desert species not to sweat, he guessed.

He paused at that thought. Without thinking, he glanced down. Spock's chest was before him.

His eyes widened.

Well. That wasn't something he'd thought about until now. Was he losing his guttermind? Maybe he'd just been thinking so much about how to fix it, and not...

Slowly, he walked over to the bedroom area, towards a reasonably-sized floor-length mirror by their dresser. Spock looked back at him, shirtless and enthralled.

If seeing himself as another person had been odd, this was even weirder. He moved his arms, entranced as the Spock before him did so, as well. It was like the first time he'd ever seen a mirror. But it didn't feel like that – instead, it felt more like this was some kind of computer program that translated all his movements into the actions of a very well-designed image of Spock.

Peering closer, he touched his face. His eyebrows, his ears... It wasn't like he'd never seen any of this before. Over the last year that they had been together, they had seen a lot of each other, and far more than this. But that was...different.

Experimentally, he smiled, but immediately looked away, hand covering his mouth. No. That was... That had felt wrong, somehow. It was just too incredibly weird to see Spock smiling like that. He didn't mind his boyfriend's blank expressions – that was just part of the way he was, and in some ways he actually liked the fact that just a brief quirk of Spock's lips was enough to make him happy. It seemed more intimate, that way, like Spock's smiles were only for him. But something this wide felt unnatural. It didn't help that the few times he truly had seen Spock smiling that way the Vulcan had invariably either been under the influence of drugs or another person.

Heart pounding, he turned to the mirror again, gazing into his face. He narrowed his eyes, then raised one eyebrow. Unconsciously, he smiled to see the familiar expression. The soft smile didn't feel so strange. It warmed him to see it – how often had Spock done this, with Jim thinking that he wished he could save this picture forever? To be able to make it himself, when it was normally distributed so rarely...

He closed his eyes. Fuck this was weird. It was so, so weird...

He opened his eyes again, looking further downwards. All sex stuff aside, this was also interesting. He touched his neck – two freckles, just on the side. He'd noticed, he guessed – how could he not? - but never really thought about it. Did Vulcans get freckles? Or was this a product of his human DNA?

And there was something else as well. Back in the briefing room, he had clasped his hands together briefly but quickly disentangled them at the spark that jolted him at the contact. He'd completely forgotten about the sensitivity of Vulcan hands. Now that he was expecting it, though, the brief touch didn't affect him much. But still he kept note of the idea, storing it in the back of his mind.

His fingers brushed across his shoulder, and he turned to look at his back in the mirror. A scar from a mission a few weeks ago. He'd been blasted from behind by some old-fashioned phaser while they were escaping with the rescued diplomat. It looked pretty ugly even now, but Spock insisted it didn't hurt. He touched it; it was totally numb. Hm.

The hair on his chest. Jim shaved, himself, so this felt a bit weird. He did it because he felt it looked better (and with how often he found himself without a shirt on a mission, he thought that was a reasonable consideration), but Spock had never cared about things like that. He did wonder sometimes, though – from the limited experience he'd had with other Vulcans, they had seemed quite hairless compared to Humans. It might just have been that Spock came from a hairier race of Vulcans, though, he guessed.

The skin was drier than Jim's own, but rougher. It had taken a little while to get used to in the beginning. And, of course, behind it all was the green tinge of copper-based blood. He narrowed his eyes, pressing down on the skin.

And there was another scar, and another. He looked for the third, but found only a pale green line. Spock always seemed to get injured too much on missions. He insisted it was for the best since the Captain was more important and that, at any rate, Vulcans could heal better than Humans so it was safer if he were hurt. That'd always pissed him off, though – yeah, he was the captain, but where would he be without Spock? And just because he could heal didn't mean he didn't feel pain. Telepathically healing himself, or telepathically doing anything, always seemed to take a lot out of him.

He blinked at that thought, and automatically tried to test his telepathic abilities. They failed, of course – even if he had known how to do it, there was the simple fact that no-one else was around. Who exactly would he look into? Besides, weren't Vulcans really big about not peeking into peoples' minds without their permission?

And on the subject of 'permission'... this wasn't bad, was it? They were going out, after all. Sure, that didn't translate into 'use my body whenever you want', but... this was kinda different, wasn't it? It wasn't like he'd be seeing anything he hadn't before. Really, was it that different from masturbating to him, which he'd done heaps of times before? He'd call him up and ask him, but he was probably very busy and anyway, asking 'can I use your body to masturbate with it' sounded...weird.

Shrugging mentally, he turned his attention back to the mirror in front of him. Spock looked back, gazing at himself seriously. And holy shit, but he would never get over this. He reached for the front of his trousers, unable to look away from the Spock in the mirror doing so, too. He touched the front, squeezing, and jumped. The image in front of him – of Spock fondling himself – it was downright hot. He knew this was really weird – wasn't he basically masturbating to himself? - but right now, he didn't really give a shit.

Kneeling down in front of the mirror, he unbuttoned the front of his pants. Already his reflection was flushed a deep green, and Jim licked his lips, pulse quickening at the expression of want on Spock's face. Unable to take it anymore, he pushed down his Starfleet regulation underwear, bringing out his olive-coloured cock. He squeezed it, and gasped in pleasure – but not only because of his dick. He had reminded himself about Vulcan hands, but he had thought to test that out by licking his fingers or whatever – the sort of thing he normally did to Spock. That just holding his hand tightly around his dick could also make the nerves of his hand sing... Well, it was an absolutely wonderful arrangement, if he did say so himself.

He shifted closer, eyes fixated on the image before him. The resemblance really was uncanny. He stroked his dick, and then, with his other hand, reached it to the mirror. Somehow, seeing Spock reaching out to him so tentatively made him even harder and he stroked again. It was like this was some kind of extremely well-made hologram that responded to him instantly but couldn't be touched. And respond he did.

Almost unconsciously, Jim shifted even closer, so his knees were touching the bottom of the mirror. He stroked himself a couple more times, grunting in satisfaction. His eyes flickered from the throbbing cock in his hands to the face in front of him, gasping for breath. That was the problem – or maybe the awesome thing – with this whole situation: Spock didn't exactly hold back in bed, but there were some things about a lifetime of suppressing visible displays of emotion that couldn't be overcome in just a few years, so he still tended to be quite a bit less expressive than Jim was even at the brink of orgasm. Jim didn't mind – he was used to it, and it was just one of the many quirks that made Spock Spock. But if nothing else, it had attuned him to expect less. So when he saw a Spock in front of him that was just as visually demonstrative as he himself usually was...well, his mind made the mental mathematics.

And it was fucking hot.

He squeezed tightly, and the Spock gasped, mouth opening. Without missing a beat, Jim licked his lips, almost groaning at the image in front of him. It was like a feedback loop – the more turned on he got, the hotter the Spock in the mirror become, which made him even more aroused. Jim pressed his thumb to the head of his dick and abruptly realised that he was close to coming; this was the fastest he'd been in a long while.

Finally, he reached his other hand up. Tentatively, he licked the fingertip. Immediately his eyes flew closed, his nerves spasming with waves of pleasure. Fuck, it was really this strong?! He licked another, just slightly, and shivers wracked his entire body. Fucking hell, no wonder Spock enjoyed this so much! It felt good around his dick, too, of course, but there it was hard to separate the two sources of pleasure. When he wasn't doing anything other than licking himself it became much more clear.

Briefly, the intellectual part of him kicked in, and he licked his palm, intending to test out how it felt to lick different parts of his hand, or suck them, or bite them, or- but as he did so, his other hand reflexively tightening around his cock, he knew that there was no way he was going to be lasting that long.

Deciding that he might as well go out with a bang at this point (so to speak), he took an entire finger into his mouth, sucking on it hard, while simultaneously pulling at his cock. The resulting wave of pleasure was so intense he only just managed to keep his eyes open to watch the view in front of him. He did it again, watching the sensations swirl over Spock's face. Suddenly, he wondered how often Spock had done this himself, pulling his dick and sucking on his fingers and that, as much as the next suck and stroke did it, pushing him over the edge.

He came with a shout, his dick spurting out the excessive amounts of cum he had seen so often from Spock. He glanced at himself again, his spent cock giving a feeble twitch at the sight of of Spock so debauched.

And that was when he noticed something in the mirror he hadn't seen before – he was standing behind himself.

Jim jumped, instinctively going to stand up. After half a second, he stopped, remembering – not an imposter. Not an evil half. Just Spock in his body.

...in other words, Spock. He tensed again, waiting for the reaction. Was he unhappy? Happy? Fuck, he was unused to reading expressions in his own face...

At least one thing was obvious, though – he hadn't been the only one enjoying the view. Jim idly wondered which was weirder out of being turned on by yourself looking like someone else or someone else looking like you. And then the blue eyes in front of him flashed with heat and he knelt down beside him and kissed him and welp, looked like he'd be going for both tonight.

“Nice to see you,” Jim murmured.

“You seem to have managed that adequately without me.”

Jim backed away, looking concerned. “Sorry – do you mind?”

Spock raised an eyebrow. “Not at all. I can imagine worse ways to return to my quarters.”

With his eyes closed, it was surprisingly easy to forget they weren't in their own bodies. Spock's mouth felt different – cooler; wetter – but his tongue and his body still acted the same way. And this whole thing was cool and unexpectedly sexy and all, but it was kinda nice just to do something he knew he could do well with his boyfriend.

And then he put his hand at the back of Spock's neck and – _right_. He jumped, the bristles pressing pleasingly into his sensitive skin. Spock noticed, of course, and pulled away. Seeing his own face so close up, something in Jim jolted, and he wasn't sure whether he wanted to disentangle himself or pull Spock closer. It was like he suddenly had a twin, which should have been squicky, maybe, except he didn't actually exist, and why the fuck was he still thinking about this?

The Kirk in front of him raised his eyebrow (seriously, how the fuck was it that Spock could do it in his body when Jim normally couldn't at all?!) and took Jim's hand. Without wasting a single movement, he took the top of his forefinger and put it into his mouth, biting down just hard enough.

Stars exploded behind his eyes and Jim groaned aloud. “Fffffuck, you are – too god at that.”

Spock raised an eyebrow again and Jim tried to glare. He removed Jim's finger. “I have-”

“Less talking, more fingersucking,” Jim commaded, gesturing with his hand. “Seriously, is it always this good? Bec- _ngaaaah_.”

Spock had repeated the motion, and was now swirling his tongue around the tip. Jim brought his other hand to his mouth instinctively, and that – that was either a very good or a very bad idea. No, Jim thought as he looked at Spock before him, it wasn't a good thing at all.

He slithered his right hand under Spock's shirt, feeling the smooth chest underneath. It had been a while since he had felt a chest like this. He actually preferred it, especially against his sensitive hand. He wondered if he could convince Spock to shave. But that was beside the point, because while he was currently experiencing a very normal Vulcan thing he couldn't as a Human, there was something else he could introduce Spock to right now. He'd tried for it earlier without thinking, but if it was his body...

He reached Spock's nipple and rubbed it with his fingers. Spock actually gasped, his pupils dilating, cheeks going pink. Jim smirked, brushing it again.

“Yeah,” he drawled, pinching the nub. “You're not the only one who can do something special.”

Spock's only response was to suck hard on his fingertip which, Jim had to admit, was a pretty good response. He pinched the nipple again, and again Spock reacted accordingly.

Movement caught his eye, and Jim returned his vision to the mirror. For all that it felt odd, he had to admit that it looked pretty normal – Kirk was sucking on Spock's fingers, who was playing with Kirk's nipple. He pushed his finger more deeply into Spock's mouth, and it was like playing one of those games where you're watching from the point of view of a different character to whom you're controlling. When he moved, Spock moved.

Spock bit down on his finger again and Jim gasped, flushing again to see the Spock in the mirror. He'd never much been into the hand thing, but he had a feeling that even after he transformed back he'd develop a bit of a fetish for them, now. He pinched Spock's nipple again. That was another problem – when he did things to Spock, it looked like _he_ was the one who was feeling good. Doing things to make himself feel good rather than Spock made him feel strangely selfish.

He wondered if Spock was being confused by all of this. Judging by the focus he was bestowing upon Jim's finger – okay, fingers, and that was a very welcome development indeed – he doubted it.

He stared at Spock, forcing himself to see his boyfriend in there. The intricacies of his expression; the slight gestures that he always made. He always moved very efficiently, the urge to reign in unnecessary uses of energy instinctive. But even Spock had his habits, and if nothing else the odd shift every now and then betrayed how unused he was to this body.

Deciding that he had been distracted for far too long, he removed his hand from Spock's nipple and shoved it unceremoniously down his pants. Spock groaned, and Jim grinned. For all that it was weird...well, it was weird. Jim _liked_ weird. It was kinda kinky, really. Happily, he squeezed Spock's cock.

Spock moved on from his fingers, licking his palm now instead and kissing it. Jim automatically reached for the spots he knew Spock liked, but stopped himself. This wasn't Spock's body, now. This was his own. In theory, it should be easier to pleasure his own body than Spock's, because while they had been going out for a year, well, Jim had been in a relationship with his body for a _lot_ longer. But with Spock's body he was used to this angle, and doing it in this way. With his own, he...wasn't. He tried, anyway, and was pleased when Spock reacted as hoped.

Spock apparently also approved of this new direction, as he finally let go of Jim's hand, reaching out to take his hard dick instead. In moments Jim was panting; fuck Spock for not even having to think about this! But that just made him think about Spock stroking himself again and fuck but that was still a hot image.

He glanced at the mirror again. He stroked Spock, as did he, and they settled into a rhythm. God but they were hot. And in a weird sort of way, this was even better – normally he'd be entirely focused on Spock, but this time he could stare at both of them. The weirdness of it all was finally paying off, and Jim had to grin, even as Spock hit a particularly nice spot until his head and he groaned.

Okay, that was enough thinking. Using the image in the mirror as a guide, he stroked harder, running his thumb along the underside the way he knew he liked it. Together, they sped up their pace, pulling harder. Jim's vision swam but still he stared, vision darting between the Kirk and the Spock there.

It was becoming more and more difficult to concentrate. He was at a disadvantage – not only his dick but his hand was being pleasured as well. The hot flesh was smooth against his palm and fingers, and Spock's hand on his cock was firm. A wave was building behind his eyes. He should be able to hold off long enough for Spock to come first, right? Since he'd already come, and since Spock was normally so good at reigning himself in. Now that he was in Spock's body, he should be able to do that, too.

He tightened his hold, ignoring the jolts of pleasure being sent up his arm. Focusing on Spock's reflection, he did his best to please him as best as he could. Spock, not one to be outdone, also picked up the pace, rubbing at just the right places. Jim grit his teeth. He could do this, he knew it!

Spock picked up his other hand. Before he could protest, his thumb was in Spock's mouth, being sucked hard.

It was incredible. Everything went white as ecstasy coursed through him. His whole body spasmed, coming over Spock and the ground.

He blinked, dazed, as the world came into vision again. “What the fuck.”

The Kirk in front of him smiled smugly. It wasn't a good look. Jim narrowed his eyes.

Before Spock could say anything at all, he shoved his hand up Spock's command gold shirt, pinching his nipple hard and squeezing at one place under the head that he knew could undo him like nothing else. Taken by surprise, Spock, too came, eyes and fists clenched.

Slowly, Spock's eyes fluttered open. Jim smiled.

“Well, that might just be the third weirdest sex I've ever had. Not that I'm complaining!”

Spock raised his eyebrow. “Should I ask?”

Jim glanced towards the mirror. His neck was starting to twinge from turning to one side so much; perhaps they should swap places? Spock turned as well. The image of them, still half-clothed, flushed and breathing heavily and covered in come...

Jim grinned. “Nah. I think we can think of something better to do...”


End file.
